private void btnThemHopDong_Click(object sender, EventArgs e)
{
this.Hide();
frmHopDong frm = new frmHopDong();
frm.ShowDialog();
this.Close();
}
private void btnHopDong_ItemClick(object sender, ItemClickEventArgs e)
{
var frmHopDong = new NghiepVu.frmHopDong();
frmHopDong.ShowDialog();
}